May Reduce Vitamin A benefits Appearance of Acne Topical vitamin Vitakin is considered the gold standard by many skin-health experts to help with acne. The U. Medically reviewed by Jennie Olopaade, PharmD, RPH — By Megan Ware, RDN, L.

Vitamin A benefits -

At the end of the trial, more lung cancers were discovered in the beta-carotene group than in the no beta-carotene group 23 vs. Three other clinical trials have found no relationship between taking vitamin A or beta-carotene supplements and lung cancer incidence or mortality [ 74 ].

One trial randomized 22, male physicians age 40—84 years to take 50 mg beta carotene on alternate days or a placebo for 12 years [ 75 ]. The results showed no differences between the groups in number of cases of lung cancer or any malignant neoplasms or number of deaths from cancer.

Another trial randomized 7, women mean age None of the supplements had any significant effect on total cancer incidence or cancer mortality, including from lung cancer.

A third trial included 29, healthy men and women age 40—69 years who were living in Linxian, China, where micronutrient deficiencies are common [ 77 ].

The study randomized participants to take either a placebo or one of four vitamin and mineral combinations including one providing retinol and zinc and another providing beta carotene, vitamin E, and selenium for 5.

The investigators followed participants for an additional 10 years after they stopped taking the supplements. The nutrient doses in the supplements were equivalent to or twice as high as U. recommended intakes, but the study report did not provide the exact doses. During both the intervention and follow-up periods, lung cancer death rates did not differ among the five groups, even when the investigators further analyzed the results for differences by age, sex, and smoking status.

The CARET and ATBC study results suggest that large supplemental doses of beta-carotene with or without retinyl palmitate have detrimental effects in current or former smokers and workers exposed to asbestos. However, the other studies described above that used similar vitamin A doses but had smaller proportions of current or former smokers do not raise this concern.

Among nonsmokers, beta-carotene and vitamin A supplements do not appear to affect the risk of cancer. AMD is the leading cause of significant vision loss in older people [ 78 ]. Because of the role of oxidative stress in AMD pathophysiology, supplements containing carotenoids with antioxidant functions, such as beta-carotene, lutein, and zeaxanthin, might be useful for preventing or treating this condition.

Lutein and zeaxanthin which are not precursors of vitamin A , in particular, accumulate in the retina, the tissue in the eye that is damaged by AMD. The AREDS trial found that participants with a high risk of developing advanced AMD i.

The follow-up AREDS2 study confirmed the value of this supplement in reducing the progression of AMD over a median follow-up period of 5 years [ 72 ]. However, this follow-up study showed that adding lutein 10 mg and zeaxanthin 2 mg or omega-3 fatty acids to the formulation produced no additional benefits.

Importantly, the follow-up study also revealed that beta-carotene was not a required ingredient; the original AREDS formulation without beta-carotene provided the same protective effect against developing advanced AMD.

A subsequent study monitored dietary intakes of several nutrients in 4, AREDS participants and 3, AREDS2 participants mean age 71 years for a median of Participants in the two highest quintiles of intakes for vitamin A, beta-carotene, or lutein and zeaxanthin had a lower risk of progression to late AMD.

At the end of the 5-year AREDS2 trial, participants were all offered the final AREDS2 formulation that included lutein and zeaxanthin in place of beta-carotene. Researchers followed up with 3, of these participants for an additional 5 years [ 73 ].

This finding confirmed the benefit of replacing beta-carotene with lutein and zeaxanthin. Individuals who have or are developing AMD should talk to their health care provider about their vitamin A intakes and the supplement formulations used in the AREDS studies.

In , measles was responsible for more than , deaths around the world, mostly in young children in low-income countries [ 81 ].

A major risk factor for severe measles is vitamin A insufficiency. The World Health Organization recommends large oral doses of vitamin A for children living in areas with a high prevalence of vitamin A deficiency to prevent morbidity and mortality, including from measles [ 39 ].

Recommended doses are 30, mcg RAE , IU of vitamin A once for infants age 6—11 months and 60, mcg RAE , IU every 4—6 months for age 1—5 years. However, a Cochrane Review that included six RCTs of vitamin A supplementation 15, mcg RAE [50, IU] to 60, mcg RAE [, IU], depending on age found that the supplementation did not affect risk of death due to measles, although it did help prevent new cases of measles [ 82 ].

These RCTs assessed the value of supplementation to prevent morbidity and mortality due to measles in a total of 19, children age 6 months to 5 years. Because vitamin A is fat soluble, the body stores excess amounts, primarily in the liver, and these levels can accumulate.

Acute vitamin A toxicity, also referred to as hypervitaminosis A, occurs within days to weeks after someone ingests one or a few very high doses typically more than times the RDA [ 83 ].

Resulting signs and symptoms typically include severe headache, blurred vision, nausea, dizziness, aching muscles, and coordination problems. In severe cases, cerebral spinal fluid pressure can increase, leading to drowsiness and, eventually, coma and even death [ 83 ]. Chronic hypervitaminosis A regular consumption of high doses can cause dry skin, painful muscles and joints, fatigue, depression, and abnormal liver test results [ 83 ].

Total intakes of preformed vitamin A that exceed the UL as well as some retinoid medications used as topical therapies such as isotretinoin, used to treat severe acne, and etretinate, a treatment for severe psoriasis can cause congenital birth defects [ 1 ].

These birth defects can include malformations of the eye, skull, lungs, and heart [ 14 ]. Experts advise people who are or might be pregnant and those who are lactating not to take high doses more than 3, mcg RAE [10, IU] daily of vitamin A supplements [ 1 ]. Unlike preformed vitamin A, beta-carotene is not known to be teratogenic or lead to reproductive toxicity [ 1 ].

The most common effect of long-term, excess beta-carotene is carotenodermia, a harmless condition in which the skin becomes yellow-orange [ 3 ]. This condition can be reversed by discontinuing beta-carotene ingestion. The FNB has not established ULs for beta-carotene and other provitamin A carotenoids [ 3 ].

However, the FNB advises against the use of beta-carotene supplements for the general population, except as a provitamin A source to prevent vitamin A deficiency. The FNB has established ULs for preformed vitamin A that apply to both food and supplement intakes [ 5 ].

The FNB based these ULs on the amounts associated with an increased risk of liver abnormalities in men and women, teratogenic effects, and several toxic effects in infants and children.

However, many dietary supplements such as multivitamins do not provide all of their vitamin A in retinol or its ester forms. For example, the vitamin A in some supplements consists partly or entirely of beta-carotene. That amount is above the UL for children from birth to 8 years but below the UL for older children and adults.

Are you a healthcare practitioner? Yes No. Search All Content Magazine Podcasts Lab Companies Lab Tests Live Classes Bootcamps Health Categories. Basic Lab Markers. Case Studies. GI Health. Herbal Medicine Fact Sheets. Lab Interpretation.

Men's Health. Mental Health. Metabolic Management. Nutrient Fact Sheets. Research Studies. Running Your Business. Women's Health. What is Vitamin A's Role in The Body? Eyesight Vitamin A is essential for proper functioning in many parts of the eye, including the cornea, conjunctival membranes, and retina.

Gene Expression Vitamin A has various roles in gene expression. Immunity Retinoic acid is found in the mucosal lining of the pulmonary system, digestive tract, and urinary tract.

Development Vitamin A is essential for the formation of various organs, including the heart, lungs, and eyes. Red Blood Cell Production Red blood cells RBCs are responsible for carrying oxygen throughout the body. How to Test Vitamin A Levels Vibrant America's Vitamin A blood test checks levels of retinol in the blood, with the reference range of 20 to 60 micrograms mcg per deciliter dL.

How to Make Sure You Are Getting Enough Vitamin A in Your Diet The Food and Nutrition Board at the National Academies of Sciences, Engineering, and Medicine created dietary recommendations for vitamins and minerals called Dietary Reference Intakes DRIs.

Vitamin A RAE Requirements for pregnant and lactating women often differ from the general population due to increased nutritional demands.

The information provided is not intended to be a substitute for professional medical advice. Always consult with your doctor or other qualified healthcare provider before taking any dietary supplement or making any changes to your diet or exercise routine.

Lab Tests in This Article Vitamin A. Micronutrients Panel. Whole Blood. The Micronutrients Panel measures various vitamins and minerals to evaluate nutritional deficiencies and abnormalities.

Subscribe to the Magazine for free. to keep reading! Subscribe for free to keep reading, If you are already subscribed, enter your email address to log back in. We make ordering quick and painless — and best of all, it's free for practitioners. Sign up free. Latest Articles View more in. Few studies have shown that taking vitamin A supplements will help prevent or treat cancer.

In fact, there is some evidence that it may be harmful. Taking beta-carotene or vitamin A supplements has been linked to a higher risk of lung cancer in people who smoke or drink alcohol.

However, some researchers say more studies are needed to confirm this. One preliminary study suggests that a topical form of vitamin A may reduce abnormal growth of cells on the cervix, called cervical neoplasia.

Researchers are also investigating retinoids, a synthetic form of vitamin A, for skin cancer. People with certain types of skin cancer tend to have lower levels of vitamin A and beta-carotene in the blood. However, studies that have looked at whether taking higher amounts of vitamin A or beta-carotene would prevent or treat skin cancer have had mixed results.

The body can also make vitamin A from beta-carotene and other carotenoids, which are fat-soluble nutrients found in fruits and vegetables that give them their color.

By eating these beta-carotene-rich foods, you can increase levels of vitamin A in your body. Tablets or capsules are available in a variety of doses. The tolerable upper limit, or safe upper limit, is 10, IU. For any dose close to that amount, a doctor should help you determine the amount to take.

Most multivitamins contain the recommended dietary allowance RDA for vitamin A. Unlike vitamin A, beta-carotene does not build up in the body. However, there is some evidence that high doses of beta-carotene can carry some risk.

Talk to your doctor before taking more than the recommended amount. Studies often use high doses of vitamin A. However, such high doses can be toxic. A doctor should monitor any high-dose therapy any dose approaching the level of 10, IU for an adult, or above the recommended daily allowance for a child.

Because of the potential for side effects and interactions with medications, you should take dietary supplements only under the supervision of a knowledgeable health care provider. Taking too much vitamin A when you are pregnant can cause serious birth defects.

Because all prenatal vitamins contain some vitamin A, you should not take a separate vitamin A supplement. Synthetic vitamin A can cause birth defects. Women who are pregnant or trying to become pregnant shouldn't take this form of vitamin A. Too much vitamin A is toxic and can cause liver failure, even death.

Symptoms of vitamin A toxicity include:. Vitamin A from foods is considered safe. But you can get too much from supplements. For adults, 19 and older, the tolerable upper limit for vitamin A is 10, IU per day.

Talk to your doctor before taking any dose close to that amount. People who have liver disease or diabetes should not take vitamin A supplements without their doctor's supervision.

Both vitamin A and beta-carotene may increase triglycerides, which are fats in the blood. They may even increase the risk of death from heart disease, particularly in smokers. Vitamin A is found in many different vitamin formulas.

Supplements that say "wellness formula," "immune system formula," "cold formula," "eye health formula," "healthy skin formula," or "acne formula," all tend to contain vitamin A.

If you take a variety of different formulas, you could be at risk for too much vitamin A. If you take large doses of vitamin A, you may want to avoid eating carob.

It increases the amount of vitamin A available in your body. If you are being treated with any of the following medications, you should not take vitamin A without first talking to your health care provider:. Tetracycline antibiotics: People who take a type of antibiotic called tetracyclines and also take high doses of vitamin A may be at risk for a condition called intracranial hypertension, which is a rise in the pressure of brain fluid.

Tetracyclines include:. Antacids: One study suggests that the combination of vitamin A and antacids may be more effective than antacids alone in healing ulcers.

Anticoagulants blood thinners : Long-term use of vitamin A or taking high doses may increase the risk of bleeding for those taking blood-thinning medications, particularly warfarin Coumadin.

Talk to your doctor before taking vitamin A. Cholesterol-lowering medications bile acid sequestrants : The medications cholestyramine Questram and colestipol Colestid may reduce your ability to absorb vitamin A and lead to lower levels in your body.

A water-soluble form of vitamin A may help. Another class of cholesterol-lowering medications called statins may actually raise vitamin A levels in your blood. Doxorubicin: Doxorubicin is a medication used to treat cancer. Test tube studies suggest that vitamin A may make the action of doxorubicin stronger.

More research is needed to understand the effect. If you are undergoing treatment for cancer, ask your oncologist before taking vitamin A or any supplement.

Medications processed by the liver: Taking high doses of vitamin A along with some other medications that are processed by the liver may cause liver damage or even liver failure.

Some examples of medications processed by the liver include acetaminophen Tylenol , carbamazepine Tegretol , isoniazid, and methotrexate. If you are taking any prescription medications, ask your doctor before taking vitamin A. Neomycin Mycifradin : This antibiotic may reduce the body's ability to absorb vitamin A, especially when taken in large doses.

Omeprazole Prilosec : Omeprazole, used for gastroesophageal reflux disease or heart burn, may interact with beta-carotene supplements. Researchers do not know whether it also affects the absorption of beta-carotene from foods.

Retinoids: These medications are a synthetic form of vitamin A and are sometimes prescribed in high doses. People who take retinoids should not take additional vitamin A supplements. In addition, these drugs can cause severe birth defects.

Women of child-bearing age must have two negative pregnancy tests and be on two forms of birth control before taking these medications. Anyone taking retinoids will be monitored closely by their doctor. Retinoids include:.

Tretinoin Retin-A is usually prescribed as a skin cream to treat acne or reduce wrinkles and is not as concentrated as other retinoids. However, you may still want to avoid taking a vitamin A supplement while using Retin-A.

Orlistat Alli and Olestra: Orlistat, a medication used for weight loss, and olestra, a substance added to certain foods, both prevent the body from absorbing fat and calories.

They may also prevent the body from absorbing enough vitamin A. The Food and Drug Administration FDA requires that vitamin A and other fat-soluble vitamins vitamins D, E, and K be added to food products containing olestra.

In addition, people who take either prescription orlistat or over-the-counter Alli may want to take a multivitamin. Alberts D, Ranger-Moore J, Einspahr J, et al. Safety and efficacy of dose-intensive oral vitamin A in subjects with sun-damaged skin. Clin Cancer Res.

Antoon AY, Donovan DK.

Vitamin A benefits Ginseng for stress relief main forms of benefots A in the human diet are preformed vitamin Vitamin A benefits Vitamni, retinyl estersand provitamin Vitamin A benefits benevits such as alpha-carotene and beta-carotene benfits are converted to retinol. Preformed vitamin A comes Vitwmin animal Vitanin, fortified foods, and vitamin supplements. Vitamin A benefits are found naturally Viamin plant Vtamin. There are other types of carotenoids found in food that are not converted to vitamin A but have health-promoting properties; these include lycopene, lutein, and zeaxanthin. Vitamin A is currently listed on the Nutrition Facts label measured in international units IU. However, the Institute of Medicine lists the Recommended Dietary Allowances RDA of vitamin A in micrograms mcg of retinol activity equivalents RAE to account for different absorption rates of preformed vitamin A and provitamin A carotenoids. The evidence suggests that eating a variety of foods rich in vitamin A, especially fruits and vegetablesis protective from certain diseases, though the health benefit of vitamin A supplements is less clear.

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